Cancer cells are like all the cells in our body, in that they need certain basic building blocks – amino acids – in order to reproduce. There are 20 amino acids found in nature. The amino acid serine is often found in abundance in patients with certain types of breast cancer, lung cancer, and melanoma. The overproduction of this amino acid is often required for the rapid and unregulated growth characteristic of cancer.
Scientists at the Scripps Research Institute (TSRI) wondered if there was a way to take advantage of the relationship between cancer cell proliferation and serine. They examined a large library of molecules -numbering 800,000 – to find an enzyme that inhibited serine production. After much research, the group found 408 contenders that could possibly work. This list was again narrowed down to a smaller set of seven, ending with one promising candidate. This molecule, 3-phosphoglycerate dehydrogenase (PHGDH), seemed to inhibit the first step in a cancer cell’s use of serine to reproduce itself.
Luke L. Lairson, assistant professor of chemistry at TSRI and principal investigator of cell biology at the California Institute for Biomedical Research remarked, “In addition to discovering an inhibitor that targets cancer metabolism, we also now have a tool to help answer interesting questions about serine metabolism.”
What does this mean for cancer patients in the future?
Discovering an enzyme that inhibits serine production means that a key process in cancer cell proliferation can be slowed down or even stopped. Interfering with cancer cell metabolism could be a pathway to treatment. Potentially, adding the molecule PHGDH to cancer cells disturbs the basic need of cancer cells to divide and reproduce rapidly. Obviously this finding points to years of further research and drug development. But discovering this key relationship between serine over-production and a molecule that slows it down could be a model for new cancer treatments in the future.